In the previous episode of How it Works, we told you about HE shells
and the way they deal damage to ships and their modules.
In today's episode, we'll discuss the main reason behind HE shells’ popularity—
their ability to start fires.
How it Works
A fire aboard a ship is very dangerous and can deal serious damage.
In our game,
they can start only after a hit from a high-explosive shell, rocket, or airbomb.
There's no other way.
Even if an HE shell explodes near the ship
and its modules are in the damage area and lose HP, there will be no fire.
Now let's return to our Fuso.
A high-explosive shell hit the battleship
and it doesn't matter if it penetrates armor or not,
the probability of causing a fire will be calculated anyway.
However, there's one exception.
The chance of fire is not calculated
if the part of the ship receiving the hit is already on fire.
In our game, there can be only four fires aboard a ship simultaneously—
one on the bow, one on the aft, and two in the central part.
By the way, the Fire Prevention skill decreases this number to three,
so there can be only one fire in the central part.
Let's get back to our example.
If the part of Fuso hit by an HE shell isn’t burning already,
the calculation of the fire probability occurs.
All HE shells in World of Warships have a chance of causing a fire.
It's measured as a percentage and depends on the caliber,
amount of explosive matter in the shell, and the ship's nation.
You can see it in the Port.
However, all ships in the game
have a base coefficient of anti-fire protection,
which depends on the ship's tier and hull (stock or top version).
You can find this coefficient on the Wargaming Wiki in the Fire article.
Apart from this, let's equip the ship that’s shooting at Fuso
with all the modifiers that increase the chance of fire,
and improve the anti-fire protection of the battleship at the same time.
Let's calculate what we have now.
Multiply the base coefficient of Fuso's fire protection
by the coefficients provided by Damage Control System Modification 1
and the Fire Prevention commander skill.
Then we multiply the obtained result
by the sum of the base fire chance of Pensacola's HE shells
divided by 2 if the Inertia Fuse skill is learned,
Victor Lima and India X-Ray signals
and the Demolition Expert Commander skill.
So, the resulting chance of fire is 11.8%.
Now, let's dismount all the modifications from our Fuso and retrain its Сommander.
As a result, the chance of causing fire increased to 13.8%.
As you can see, if you don't improve the fire protection of your battleship,
the difference will be slightly higher than 2%.
This seems insignificant,
but if your battleship is hit by 100 shells in a battle,
it's 2 fewer fires on average.
A fire doesn't harm modules nor does it damage a ship's parts;
it directly "burns" the HP indicator.
How much HP a ship loses during a fire depends on its type.
Aircraft carriers lose 1% of their full HP value per second,
all other ship types lose 0.3% per second.
Another important parameter of a fire is its duration.
Destroyers and cruisers burn for 30 seconds,
aircraft carriers—for 5 seconds,
and battleships—for 60 seconds.
There are exceptions, though.
For example, Graf Spee burns for 45 seconds.
Alaska, Stalingrad, Azuma, and Kronstadt burn for 60 seconds.
It would seem that these numbers are not so serious,
but one fire takes away 5% from carriers’ total HP,
9% from destroyers and cruisers, and 18% from battleships.
As you remember, the maximum number of simultaneous fires on one ship is four.
So, a battleship can lose 72% of its HP in a minute,
and our Fuso will be left with a mere 15,988 HP.
That's why you need to and should reduce the fire duration.
For example, the combination of the India Yankee signal,
Basics of Survivability skill, and Damage Control System Modification 2
will reduce the duration of a fire on our battleship to 35 seconds.
As a result, even after four fires, Fuso will be left with 36,544 HP.
Don't forget about Damage Control Party either,
especially since it's impossible to set a ship ablaze when it's active.
However, you can't extend the duration of a fire,
even with the most intensive shelling,
which is why you should aim at a ship’s center or aft if its bow is on fire.
But as soon as the fire dies out, feel free to return to the bow.
And remember that fires don't spread on a ship independently, they need help.
Apart from inflicting serious damage, fires cause additional problems
by increasing the detectability range of a burning ship by 2 kilometers.
Torpedoes are similar to fires by their damage mechanic.
But we'll tell you about them in the next episode of How it Works.
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